Jacquie and All, 

I also find it hard to believe that mature milk becomes deficient at some specific or random point in time.  Why should it?  And what would be the mechanisms to create such deficiencies?  I will remain open-minded, but am not holding my breath for any science to support this.  

Of course there are changes from colostrum to mature milk.  The findings from the 2016 study below suggest "that the metabolome of pre-term milk changes within 5-7 weeks postpartum to resemble that of term milk, independent of time of gestation at pre-mature delivery."

In:  Nutrients 2016 May 19;8(5). pii: E304. doi: 10.3390/nu8050304.

Title:  The Effect of Gestational and Lactational Age on the Human Milk Metabolome.

Authors:  Sundekilde UK, Downey E, O'Mahony JA, O'Shea CA, Ryan CA, Kelly AL, Bertram HC.

Abstract: "Human milk is the ideal nutrition source for healthy infants during the first six months of life and a detailed characterisation of the composition of milk from mothers that deliver prematurely (<37 weeks gestation), and of how human milk changes during lactation, would benefit our understanding of the nutritional requirements of premature infants. Individual milk samples from mothers delivering prematurely and at term were collected. The human milk metabolome, established by nuclear magnetic resonance (NMR) spectroscopy, was influenced by gestational and lactation age. Metabolite profiling identified that levels of valine, leucine, betaine, and creatinine were increased in colostrum from term mothers compared with mature milk, while those of glutamate, caprylate, and caprate were increased in mature term milk compared with colostrum. Levels of oligosaccharides, citrate, and creatinine were increased in pre-term colostrum, while those of caprylate, caprate, valine, leucine, glutamate, and pantothenate increased with time postpartum. There were differences between pre-term and full-term milk in the levels of carnitine, caprylate, caprate, pantothenate, urea, lactose, oligosaccharides, citrate, phosphocholine, choline, and formate. These findings suggest that the metabolome of pre-term milk changes within 5-7 weeks postpartum to resemble that of term milk, independent of time of gestation at pre-mature delivery.  KEYWORDS: NMR; human milk; infant; metabolites; metabolomics; nutrition; pre-term"

With best regards,

Debbie

Debra Swank, RN BSN IBCLC
Program Director
More Than Reflexes Education
Ocala, Florida USA
http://www.morethanreflexes.org

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